Aortic diseases constitute a heterogeneous group with different etiologies, variable clinical presentation, histopathology and natural history [1]. The aortic pathology may be congenital or acquired, the latter one including degenerative, inflammatory, traumatic and neoplastic lesions, and can lead to AAS, TAA and AAA or to chronic AD [2]. AAS represents a challenging diagnosis and a life-threatening condition requiring prompt diagnosis and treatment; it is mainly represented by AD followed by IAH, PAU and traumatic aortic injury [3]. An aortic aneurysm is conventionally defined as an aorta that is dilated to at least 1.5 times its expected normal diameter [4]. This definition pertains to the abdominal and descending thoracic aorta, whereas it is not well suited for aneurysms of the aortic root and the ascending thoracic aorta in which even less than 1.5 times dilatation (i.e., ≤5 cm aortic diameter) can be assessed to be aneurysmatic depending upon the clinical setting [5]. Because of their clinical complexity, aortic diseases require a multidisciplinary approach for diagnosis, treatment and follow-up, the better outcomes being achieved in referral centers by a team-based approach. The setting up of a multi-disciplinary aortic team for the discussion of complex aortic pathology cases has been proposed by some Authors and it is supported by ACC/AHA [4,[6], [7], [8]]. The aortic team involves at least surgeons and radiologists, but other medical professionals such as cardiologists, geneticists, rheumatologists/internal medicine specialists and pathologists, can be part of it. These latter professionals may significantly contribute to the diagnosis and to the clinical management of these patients, and even, in hereditary and familial forms of aortopathies, of blood relatives that might not yet have overt signs or symptoms of the disease [9]. The cardiovascular pathologist has the task to examine the aortic specimens, to diagnose and classify the aortic lesions [10]. The aortic specimens for histology are mainly obtained from thoracic aorta during emergency or elective surgical procedures requiring aortic grafting, and less frequently from organ/tissue (i.e., cardiac or heart valve) donors, whereas abdominal aortic segments may be sampled during post-mortem or (more rarely) surgical and organ donation procedures [2,4,11,12].

In the last decade, the histological definitions and classifications of the aortic pathology have been going through revisions that are addressed to an etiopathogenetic approach and are looking for both clinico-pathologic correlations and research. Accordingly, the contribution of the cardiovascular pathologist to the study of aortopathies is steadily increasing and often influencing the post-operatory management of patients, but new challenges are emerging for the pathologist in both diagnosis and research [13,14]. Herein a review of the pathobiology of aortic diseases is being presented for reference by pathologists participating in the aortic teams; the role of the pathologist in the aortic team is discussed.